Implantable biomedical microsystems for neural prostheses

Abstract

In the following article, the technologies to fabricate polyimide-based thin and flexible substrates with monolithically integrated electrode arrays and printed circuit boards (PCB) for hybrid electronic assemblies as well as an assembling technique that connects bare electronic dice with flexible PCBs are presented. The concept of modular, flexible biomedical microsystems as neural prostheses is introduced in general and described in detail in three examples. A cuff electrode with integrated multiplexer circuitry and standard implantable cables represents the combination of microtechnology with precision mechanics; a sieve electrode used as an implant in peripheral nerve regeneration studies demonstrates the next level of integration density but still uses a cable connection; and last, joint effort to fabricate the demonstrator of a vision prosthesis that is completely implantable in the eye with a wireless link for energy supply and data transmission is presented. System design, hybrid assembling technology, and flexible multilayer encapsulation using parylene and silicone rubber are the key components for creating a new generation of neural prostheses for complex and challenging new applications

Interfacing Neurons with Carbon Nanotubes: Electrical Signal Transfer and Synaptic Stimulation in Cultured Brain Circuits

“…Clinical progresses of the numerous interface concepts proposed in basic research are limited by common recurrent problems, ranging from improper neuronal adhesion to inadequate signal stability. The success in overcoming these problems for the design of future interfaces mainly relies on the application of emerging technologies (but see also Fromherz, 2002;Stieglitz et al, 2005). Examples of current research include technologies, such as nanotechnology, that are designed to improve material/neuron junctions to be applied as implantable interfaces (Patolsky et al, 2006).…”

Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies

“…For the fabrication of neural systems with high-density electrodes, precision machining is increasingly being replaced by microelectromechanical systems (MEMS) technologies (Alivisatos et al 2013). In general, these MEMS-based devices rely on polymers (Stieglitz et al 2005) or silicon Wise et al 2008) as substrate materials, with the latter enabling the co-integration of electrodes with complementary metal-oxide semiconductor (CMOS) integrated circuits performing data preprocessing and multiplexing tasks.…”

Flexible Temperature Microsensor for Application of High-Intensity Focused Ultrasound

“…(12) Platinum is selected as the sensor sensitive material, as it has a good thermal response that corresponds linearly to temperature. (13)(14)(15) There is much interest in the development of polyimide-based devices for medical applications, which include implantable microelectrodes (16) for neural prostheses, (17) micro-hotplates and microheater arrays, (18,19) and bolometers. (20) To our knowledge, no one has addressed the fabrication of a temperature microsensor to measure the temperature distribution on the skin during ultrasound exposure.…”